In the prior art, technicians have developed many forms of loudspeakers.
One of the most interesting forms of a loudspeaker is that of a moderately-sized cylinder. It is generally 60˜110 mm in diameter and is 240˜450 mm in height. This kind of loudspeaker is generally called as a monolithic loudspeaker. For example, it may serve as a voice and audio interface to an artificial-intelligence personal assistant. In addition to providing interactive voice assistant services, the monolithic loudspeaker may also be used as music and other media playback device.
Unfortunately, due to the monolithic nature of such a device, it is poorly suitable to provide a good stereophonic experience, as is achieved by a typical, separated pair of loudspeakers. In the typical, separated pair of loudspeakers, ‘left’ and ‘right’ sound channels are fed to the separated loudspeakers. The separated loudspeakers are located at different places and thus emanate a stereo sound field for a listener.
In a traditional monolithic loudspeaker, separate beams of ‘left’ and ‘right’ sound channels are formed and are fed to a speaker array in the monolithic loudspeaker, so as to at least partially emulate the sound field emanated from a separated pair of loudspeakers. However, this approach does not work well, especially at the lower range of the audible frequency range. For example, in the lower range, the high wavelength-to-array-length ratio for the monolithic loudspeaker will result in a very high “White Noise Gain”. This will lead to a very low efficiency.
Therefore, there is a demand in the art that a new solution for a monolithic loudspeaker shall be proposed to address at least one of the problems in the prior art.